We are indeed more sexually fluid than most species and given it’s “most” and not “all”, this isn’t unprecedented. It’s also not a new phenomena, in Ancient Greek and early-mid Ancient Roman societies queerness was quite common. In fact homosexuality was so prevalent that that the Romans didn’t even have a word for heterosexual/homosexual; instead one was either dominant or submissive (e.g. giving or receiving) with the assumption being that most were bisexual and would take partners as they saw fit.
Yep, Mumble is the most common, and there are still a couple groups that use Teamspeak.
Discord caps at 100 people in a call while I’ve seen good Mumble servers handle over 800.